U.S. patent application number 13/410891 was filed with the patent office on 2012-09-13 for in situ catalytic upgrading.
This patent application is currently assigned to CONOCOPHILLIPS COMPANY. Invention is credited to Joe D. Allison, Wayne Reid Dreher, JR., Wendell P. Menard, Thomas J. Wheeler.
Application Number | 20120227966 13/410891 |
Document ID | / |
Family ID | 46794473 |
Filed Date | 2012-09-13 |
United States Patent
Application |
20120227966 |
Kind Code |
A1 |
Dreher, JR.; Wayne Reid ; et
al. |
September 13, 2012 |
IN SITU CATALYTIC UPGRADING
Abstract
A system and method for in situ upgrading of crude oil is
provided. The system includes at least one injection well, at least
two first production wells, and at least one second production
well. The at least one injection well has a vertical portion and a
plurality of non-vertical portions connected to the vertical
portion. The at least two first production wells are preferably
equi-spaced and each has a horizontal portion with a first axial
direction, wherein each said horizontal portion of the first
production wells is horizontally spaced apart. The at least one
second production well has a horizontal portion with a second axial
direction. The catalytic reactor is placed at the horizontal
portion of the at least one second production well such that oil
coming through the second production well will first go through the
catalytic reactor for hydroprocessing.
Inventors: |
Dreher, JR.; Wayne Reid;
(College Station, TX) ; Allison; Joe D.;
(Fulshear, TX) ; Menard; Wendell P.; (Katy,
TX) ; Wheeler; Thomas J.; (Houston, TX) |
Assignee: |
CONOCOPHILLIPS COMPANY
Houston
TX
|
Family ID: |
46794473 |
Appl. No.: |
13/410891 |
Filed: |
March 2, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61450872 |
Mar 9, 2011 |
|
|
|
Current U.S.
Class: |
166/272.3 ;
166/52; 166/57 |
Current CPC
Class: |
E21B 43/243 20130101;
E21B 43/305 20130101; E21B 36/04 20130101 |
Class at
Publication: |
166/272.3 ;
166/52; 166/57 |
International
Class: |
E21B 43/24 20060101
E21B043/24; E21B 43/12 20060101 E21B043/12 |
Claims
1. A system for in situ upgrading crude oil within an oil reservoir
prior to production, comprising: at least one injection well having
a vertical portion and a plurality of non-vertical portions
connected to the vertical portion; at least two first production
wells parallel to each other and each having a horizontal portion
with a first axial direction, wherein each said horizontal portion
of the first production wells being horizontally spaced apart; at
least one second production well having a horizontal portion with a
second axial direction; and a catalytic reactor placed at the
horizontal portion of the at least one second production well;
wherein the horizontal portion of the at least one second
production well is vertically lower than the horizontal portion of
the at least two first production wells; the first axial direction
is substantially perpendicular to the second axial direction or are
substantially equi-spaced if more than two.
2. The system of claim 1, wherein the catalytic reactor comprises a
catalyst bed, a gas inlet and a plurality of slots for taking in
crude oil.
3. The system of claim 2, wherein the catalytic bed comprises
hydro-processing catalysts.
4. The system of claim 3, wherein the hydro-processing catalysts
are selected from the group consisting of metal sulfides, metal
carbides, refractory type metal compounds, and combination
thereof.
5. The system of claim 4, wherein the metal sulfides are selected
from the group consisting of MoS.sub.2, WS.sub.2, CoMoS, NiMoS, and
combination thereof.
6. The system of claim 4, wherein the metal carbides are selected
from the group consisting of MoC, WC, and combinations thereof.
7. The system of claim 4, wherein the refractory type metal
compounds are selected from the group consisting of phosphosides,
nitrides and borides of transition metals.
8. The system of claim 7, wherein the refractory type metal
compounds are selected from the group consisting of Co.sub.2P,
Ni.sub.2P, MoP, WP, NiMoP, Mo.sub.2N, Co.sub.4N, Fe.sub.3N,
W.sub.2N, MoB, WB, Ni.sub.2B, Co.sub.2B, and combinations
thereof.
9. The system of claim 1, wherein the injection well extends within
the oil reservoir until at least 5 meters above the bottom of the
reservoir.
10. The system of claim 2, wherein the catalytic reactor further
comprises at least one heater for heating the catalyst bed.
11. A method of in-situ upgrading crude oil within an oil reservoir
prior to production, comprising: providing an injection well within
the oil reservoir, the injection well having a vertical portion and
a plurality of non-vertical portions connected to the vertical
portion; providing at least two first production wells each having
a horizontal portion with a first axial direction, wherein each
said horizontal portion of the first production wells being
horizontally spaced apart; providing at least one second production
well having a horizontal portion with a second axial direction,
wherein a catalytic reactor being placed at the horizontal portion
of the second production well, the horizontal portion of the at
least one second production well being vertically lower than the
horizontal portion of the at least two first production wells, and
the first axial direction being substantially perpendicular to the
second axial direction or are substantially equi-spaced if more
than two; performing steam stimulation to heat the oil deposit with
the oil reservoir; injecting a combustion agent into the injection
well; and producing crude oil from the at least one second
production well.
12. The method of claim 11, wherein the catalytic reactor comprises
a catalyst bed, a gas inlet, and a plurality of slots for taking in
the crude oil.
13. The method of claim 12, wherein the catalytic bed comprises
hydro-processing catalysts.
14. The method of claim 13, wherein the hydro-processing catalysts
include metal sulfides, metal carbides, refractory type metal
compounds, or combinations thereof.
15. The method of claim 14, wherein the metal sulfides are selected
from the group consisting of MoS.sub.2, Ws.sub.2, CoMoS, NiMoS, and
combinations thereof.
16. The method of claim 14, wherein the metal carbides are selected
from the group consisting of MoC, WC, and combinations thereof.
17. The method of claim 14, wherein the refractory type metal
compounds include phosphosides, nitrides or borides of transition
metals.
18. The method of claim 17, wherein the refractory type metal
compounds are selected from the group consisting of Co.sub.2P,
Ni.sub.2P, MoP, WP, NiMoP, Mo.sub.2N, Co.sub.4N, Fe.sub.3N,
W.sub.2N, MoB, WB, Ni.sub.2B, Co.sub.2B, and combinations
thereof.
19. The method of claim 12, wherein the catalytic reactor further
comprises at least one heater for heating the reactor.
20. The method of claim 11, further comprising the following step:
introducing hydrogen through the gas inlet to the catalytic
reactor.
21. The system of claim 11, wherein the combustion agent is
selected from oxygen, oxygen-enriched air, and the combination
thereof.
Description
PRIOR RELATED APPLICATIONS
[0001] This application is a non-provisional application which
claims the benefit of and priority to U.S. Provisional Application
Ser. No. 61/450,872 filed Mar. 9, 2011, entitled "In Situ Catalytic
Upgrading," which is hereby incorporated by reference in its
entirety.
FEDERALLY SPONSORED RESEARCH STATEMENT
[0002] Not applicable.
FIELD OF THE INVENTION
[0003] The invention relates to in situ hydrocarbon upgrading
system and method, and more particularly to an in situ oil
upgrading for upgrading the crude oil before production.
BACKGROUND OF THE INVENTION
[0004] Heavy oils such as bitumen and oil sands can be very
difficult to access due to their high viscosity. In situ upgrading
is an enhanced recovery technique that aims to upgrade heavy crude
oil and bitumen while still within the subsurface of the earth,
making the hydrocarbons easier to produce and transport. Attempts
have been made to address this challenge by using in situ
combustion approaches, solvent extraction, radio frequency
(including microwave radiation) heating, and thermal resistive
heating. Although each of these attempts has shown some technical
merit, no method currently exists which addresses all of the
requirements of a commercially viable process.
[0005] In situ upgrading has also been attempted by using a solvent
process known as "Vapex." In this approach, a solvent mobilizes the
oil by decreasing its viscosity through a dissolution effect.
During this process, asphaltenes, heteroatoms, and heavy metals may
precipitate, resulting in upgraded oil. Solvent to oil ratios are
high, however, and make this process economically unfeasible. In
addition, as larger molecules precipitate, flocculation may occur
which may lead to the clogging of the producing well.
[0006] A similar approach has been to simply use a catalyst bed
around the producer well in a modified toe to heel air injection
(THAI) process. This approach is limited to the amount of upgrading
that may occur and does not utilize hydrogen.
[0007] Although the prior art methods have achieved success, they
could be further improved with novel combinations of techniques
and/or novel well configurations, to further increase production
and/or decreases production costs. Thus, what is needed in the art
are improved, cost effective methods of in situ upgrading of
hydrocarbon deposits.
SUMMARY OF THE INVENTION
[0008] The use of the word "a" or "an" when used in conjunction
with the term "comprising" in the claims or the specification means
one or more than one, unless the context dictates otherwise.
[0009] The term "about" means the stated value plus or minus the
margin of error of measurement or plus or minus 10% if no method of
measurement is indicated.
[0010] The use of the term "or" in the claims is used to mean
"and/or" unless explicitly indicated to refer to alternatives only
or if the alternatives are mutually exclusive.
[0011] The terms "comprise", "have", "include" and "contain" (and
their variants) are open-ended linking verbs and allow the addition
of other elements when used in a claim.
[0012] The following abbreviations are used herein:
TABLE-US-00001 ICU In situ combustion CSS Cyclic steam stimulation
THAI Toe to heel air injection
[0013] As used herein a "Fishbone" configuration is defined as a
well having an initially vertical portion and a plurality of
non-vertical, deviated portions connected to the vertical portion
and extending in the oil reservoir. The non-vertical portions of a
Fishbone well can further progress through the reservoir at angles
different from the original angle.
[0014] As used herein, "in situ upgrading" refers to a system
and/or process that upgrades crude oil, i.e. hydro-cracks the heavy
oil, prior to production. In other words, the process occurs inside
the ground or hydrocarbon reservoir.
[0015] The objective of the present invention is to upgrade
mobilized oil within a reservoir prior to production of the oil to
the surface. Generally speaking the invention requires pushing
fluid through a reservoir, the lighter components of which then
escape laterally through production wells. The heavier components
sink to a lower horizontal production well, where it optionally
filters through porous catalysts contained in the wellbore, thus
being upgraded before production. The unique placement of the
injector and producer wells optimizes production in this
method.
[0016] In preferred embodiments, the present invention utilizes an
injection well having a Fishbone configuration that facilitates the
moving of a combustion front in the reservoir. In addition, by
using two production wells having equi-spaced (parallel if only
two) horizontal portions and another production well having a
lower, but perpendicular horizontal portion, the mobilized oil can
be more easily drained and produced through the lower production
well, while gases escape through the higher production wells. In
situ upgrading of the crude oil is realized by adding the catalytic
reactor to the lower but perpendicular horizontal portion of the
production well, so that the oil taken in the production well will
first undergo hydro-processing in the catalytic reactor to further
increase the mobility and quality of the oil. If desired, this
lower portion can also be equipped with heaters to reduce oil
viscosity and/or drive the catalytic reactions.
[0017] According to one aspect of the present invention, there is
provided a system for in situ upgrading crude oil within an oil
reservoir prior to production. The system includes at least one
injection well, at least two first production wells, and at least
one second production well. The at least one injection well has a
vertical portion and a plurality of non-vertical portions connected
to the vertical portion. The two first production wells are
parallel to each other (but are roughly equi-spaced if more than
two), and each has a horizontal portion with a first axial
direction, wherein each said horizontal portion of the first
production wells is horizontally spaced apart.
[0018] The at least one second production well has a horizontal
portion with a second axial direction. The catalytic reactor is
placed at the horizontal portion of the at least one second
production well such that oil coming through the second production
well will first go through the catalytic reactor for
hydro-processing. Preferably, the horizontal portion of the at
least one second production well is vertically lower than the
horizontal portion of the at least two first production wells to
ensure better oil drainage and production. Preferably, the first
axial direction of the first production wells is substantially
perpendicular to the second axial direction of the second
production well (or equi-spaced if more than two).
[0019] Of course, additional production wells can be used and the
placement varied accordingly. Furthermore, when we refer to
placement, the placement need not be exact, but can vary according
to convenience, depending on surface structures or subsurface
impediments. Thus, the placement of parallel or perpendicular
wells, etc. is only a rough description.
[0020] In one embodiment, the catalytic reactor comprises a
catalyst bed, a fluid inlet for introducing the fluid required for
upgrading, and a plurality of slots for taking in the crude oil. In
another embodiment, the catalytic reactor comprises a catalyst bed,
a gas inlet, a plurality of slots for taking in the crude oil, and
heaters for heating the reactor and/or the oil so as to facilitate
the required temperatures necessary to upgrade the oil. In some
embodiments, the heaters can be thermal resistive heaters, but
other heating methods can also be used.
[0021] In one embodiment, the catalytic bed comprises
hydro-processing catalysts. Examples of the hydro-processing
catalysts include, but not limited to, metal sulfides, metal
carbides, refractory type metal compounds or the combination
thereof. The metal sulfides may include MoS.sub.2, WS.sub.2, CoMoS,
NiMoS, or combinations thereof. The metal carbides can include
Mo.sub.2C, WC, or combinations thereof. In another embodiment, the
refractory type metal compound includes phosphosides, nitrides or
borides of transition metals. In yet another embodiment, the
refractory type metal compound includes hydrogenation catalysts
such as Co.sub.2P, Ni.sub.2P, MoP, WP, NiMoP or Mo.sub.2N,
Co.sub.4N, Fe.sub.3N, W.sub.2N or MoB, WB, Ni.sub.2B, Co.sub.2B, or
the combination thereof, with optional support such as
Al.sub.2O.sub.3, TiO.sub.2, MgO, SiO.sub.2 and the combination
thereof.
[0022] The injection well, especially the non-vertical portions,
may progress within the oil reservoir to any place depending on the
need and technological limitations, except that preferably it does
not extend deeper than 5 meters above the bottom of the pay.
[0023] According to another aspect of the present invention, there
is provided a method for in situ upgrading crude oil within an oil
reservoir prior to production. The method comprises the following
steps: providing an injection well within the oil reservoir, the
injection well having a vertical portion and a plurality of
non-vertical portions connected to the vertical portion; providing
at least two first production wells each having a horizontal
portion with a first axial direction, wherein each said horizontal
portion of the first production wells being horizontally spaced
apart; providing at least one second production well having a
horizontal portion with a second axial direction, wherein the
horizontal portion of the at least one second production well being
vertically lower than the horizontal portion of the at least two
first production wells, the first axial direction being
substantially perpendicular to the second axial direction, and a
catalytic reactor being attached to the horizontal portion of the
second production well; performing cyclic steam stimulation to heat
the oil deposit with the oil reservoir; injecting a combustion
agent into the injection well; and producing crude oil from the at
least one second production well.
[0024] In a preferred embodiment, the method further comprises the
step of introducing hydrogen through the gas inlet to the catalytic
reactor.
[0025] In another embodiment, the combustion agent is selected from
oxygen, oxygen-enriched air, or the combination thereof, although
plain air and oxygen-depleted air are also applicable when the
exotherm is large. In addition, chemical oxidants such as
H.sub.2O.sub.2 or O.sub.3, or other organic and inorganic peroxides
may also be used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a schematic view showing the Fishbone
configuration of the injection well of the present invention.
[0027] FIG. 2 is a gas saturation contour for the slice of the
reservoir where the Producers 1 and 3 of FIG. 1 are situated.
[0028] FIG. 3 is a gas saturation contour for the slice of the
reservoir where the Producer 2 of FIG. 1 is situated.
[0029] FIG. 4 is a schematic view showing the Fishbone
configuration of the injection well of the present invention, where
the lower well bore is equipped with a reactor for catalytic
upgrading of hydrocarbons.
[0030] FIG. 5 is a cross-sectional view of one embodiment of the
reactor/producer 2 shown in FIG. 4.
[0031] FIG. 6 is a cross-sectional view of an alternative
embodiment of the reactor/producer 2 shown in FIG. 4.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0032] The present invention utilizes a novel well-configuration to
facilitate the application of in situ combustion in a bitumen
and/or heavy oil reservoir and offers a novel approach for
upgrading the bitumen and/or heavy oil prior to surface production.
The well configuration of interest is a fishbone well configuration
as shown in FIG. 1.
[0033] At the beginning, wells are drilled in a fishbone pattern. A
single vertical well from the surface can facilitate this drilling.
Multiple wells at angles varying from 30 to 120 degree from
vertical will be drilled into the reservoir from the single
vertical well. Additionally, these vertically deviated wells may
progress through the reservoir at angles that differ from the
original angle. This will facilitate the best placement of the well
within the reservoir. These wells will be placed anywhere within
the reservoir with the exception that the lowest well should be at
least five (5) meters above the bottom of the pay. In addition,
this process requires the use of three producer wells that will be
completed through the use of horizontal drilling technologies.
These horizontal wells can be placed near or at the base of the
reservoir pay zone, where at least one or more producers are
arranged perpendicular (or roughly equi-spaced depending on how
many are used) to one or more producer wells situated vertically
beneath the other well pairs. In FIG. 1, this process is
facilitated by two producer wells above a single, perpendicular
producer well.
[0034] Once the wells have been placed within the reservoir, they
will be used in a primary or preliminary recovery method known as
cyclic steam stimulation (CSS) or similar technique. This process
will facilitate the heating of the reservoir and preliminary
recovery of oil. Once the pay between the wells has been heated
(>80.degree. C.), the CSS processes can be shut in. The main
objective for the CSS process is to condition the reservoir by
lowering the viscosity to a level that allows for fluid
communication prior to the initiation of an in situ combustion
process. CSS is a technology known to a skilled artisan in the
field, and will not be elaborated here.
[0035] Once CSS operations are completed, the Fishbone well setup
will now be used as injector wells for the introduction of
combustion agent, for example oxygen or oxygen enriched air, into
the formation. The major driver for the recovery of oil through the
combustion process will be gravity drainage. In the present
specification, "gravity drainage" refers to a recovery mechanism in
which the oil is pushed or displaced into the production well by
the force of gravity.
[0036] For example, as the combustion agent propagates from the
Fishbone injector wells into the formation, oil and combustion gas
products will drain to the base of the reservoir. The unique aspect
of this well pair arrangement for the in situ combustion process is
that it facilitates the ability to produce oil and gas products
from separate wells. This phenomenon aides in the overall process
by removing gas products from the reservoir, which allows the oil
to flow more freely to the bottom of the reservoir where it can be
produced by Producer 2 well in FIG. 1.
[0037] Simulation results are shown in FIG. 2 to illustrate this
effect. FIG. 2 is a gas saturation contour for the slice of the
reservoir where Producers 1 and 3 are situated, and gravity
segregation of products is shown. As shown in the figure, there is
a high accumulation of gas present in this region. In other words,
gas can be produced from a dedicated gas producer that allows oil
to more freely flow to the base of the reservoir for production.
Gas production profiles can further illustrate this effect by
illustrating the majority of the gas being produced by Producers 1
and 3.
[0038] FIG. 3 is a gas saturation profile for the bottom of the
reservoir where Producer 2 is situated. As shown, it is clear that
a segregation has occurred in the reservoir where higher
saturations of gas exist and are being produced in the region above
the area where Producer 2 is located. Conversely to this, a similar
plot for oil saturation would show that the majority of the oil is
draining to the bottom of the reservoir and being produced by
Producer 2. For this process, oil is expected and can be shown to
be produced by Producers 1 and 3, but this production was early in
the cycle of the process and largely due to oil being present
around the producer wells prior to initiating the process. Once
this oil was produced, the main recovery mechanism was gravity
drainage to the bottom of the reservoir.
[0039] An extension of the above mentioned process is that the
fluid separation and gravity drainage mechanisms consistent with
this approach offer a unique opportunity to upgrade bitumen and
heavy oil subsurface.
[0040] FIG. 4 illustrates a modification to the Fishbone process
that enables in situ upgrading. As shown, Producer 2 now utilizes
an upgrading reactor. Ultimately, heated mobile oil will drain
through the slotted liner and into the producer/reactor, which is
packed with a catalyst bed. Specific catalysts that facilitate
upgrading for the process will ideally be less susceptible to
poisoning by sulfur species, water oxidation, nitrogen or heavy
metal poisoning or other forms of potential transition metal
catalyst poisoning.
[0041] Some examples of possible hydro-processing catalysts that
may be applicable are metal sulfides (MoS.sub.2, WS.sub.2, CoMoS,
NiMoS, etc.), metal carbides (MoC, WC, etc.) or other refractory
type metal compounds such as metal phosphides, borides, etc. The
refractory type metal compound includes phosphosides, nitrides or
borides of transition metals. In one embodiment, the refractory
type metal compound includes hydrogenation catalysts such as
Co.sub.2P, Ni.sub.2P, MoP, WP, NiMoP or Mo.sub.2N, Co.sub.4N,
Fe.sub.3N, W.sub.2N or MoB, WB, Ni.sub.2B, Co.sub.2B, or the
combination thereof, with optional support such as Al.sub.2O.sub.3,
TiO.sub.2, MgO, SiO.sub.2 and the combination thereof. It is not
anticipated that reduced metal catalysts will remain active for a
long period of time in this application.
[0042] Typical hydro-processing reactions will consist of impurity
removal processes, such as the removal of sulfur, nitrogen and
metals. This can improve the ultimate quality of the crude.
Hydrogen assisted removal of oxygen can lower the acid number of
the crude. Reduction of aromatics will produce "lighter"
hydrocarbons thus lowering the API gravity of the crudes. Potential
hydrocracking/isomerization reactions can provide lower carbon
number branched hydrocarbons and will improve a lower viscosity
crude. It is expected that some combination of all the above
reactions will be realized thus giving an improved quality and less
viscous crude oil.
[0043] FIG. 5 is a cross-sectional view of the reactor/producer
well. As shown, hydrogen can be injected into the reactor/producer
well by using straight or even coiled tubing. Hydro-processing
reactions of the type expected (desulfurization, olefin and
aromatic saturation, hydrocracking) can occur between hydrogen
pressures of 50 psi to several thousand psi H.sub.2. It is
anticipated to provide H.sub.2 at as high of partial pressure as
feasible. This can be from between 50 and 1200 psi H.sub.2 and
preferably between 600 to 800 psi H.sub.2. Ultimate hydrogen
pressure in practice will be determined via experimental
testing.
[0044] The space velocity of the hydrocarbon in the
catalyst/hydrogen zone should be between 0.05 to 1.0 hr.sup.-1 or
more preferably between 0.2 and 0.5 hr.sup.-1. The unique aspect of
this approach is that the hydrogen will be sufficiently separated
from the high temperatures of the combustion front due to the fact
that the main recovery mechanism is gravity separation. The
producer tubing is placed vertically near the bottom of the
reactor/producer, which promotes increased contact with the
catalyst and hydrogen prior to production.
[0045] In a separate embodiment of this invention, thermal
resistive heaters may be incorporated within the reactor/producer
wells to facilitate the required temperatures necessary to upgrade
the oil prior to production. An example of this is shown in FIG. 6.
Other heating mechanisms can also be used.
[0046] An advantage of this invention is that it allows for oils to
contact catalyst and hydrogen at required upgrading temperatures
prior to being produced. As the oil is upgraded, the viscosity will
be further reduced which will lead to an increase in the overall
recovery of the oil and limit or eliminate surface processing.
Also, the present invention allows for the successful, both
technically and economically, implementation of in situ
combustion.
[0047] The foregoing description of the present invention is
exemplary only, and other variation of the present invention can be
readily contemplated by a person having ordinary skill in the art
based on the teaching of the specification without deviating from
the spirit of the present invention. The foregoing description is
intended to be illustrative only, and not unduly limit the scope of
the appended claims.
* * * * *